ip: do not print stray prefixes in monitor mode

When running "ip monitor", accept_msg() first prints the prefix and
then calls the object-specific print function, which also does the
filtering. Therefore, it is possible that the prefix is printed even
for events that get ignored later. For example:

  ip link add dummy1 type dummy
  ip link set dummy1 up
  ip -ts monitor all dev dummy1 &
  ip link add dummy2 type dummy
  ip addr add dev dummy1 192.0.2.1/24

generates:

  [2024-07-12T22:11:26.338342] [LINK][2024-07-12T22:11:26.339846] [ADDR]314: dummy1    inet 192.0.2.1/24 scope global dummy1
       valid_lft forever preferred_lft forever

Fix this by printing the prefix only after the filtering. Now the
output for the commands above is:

 [2024-07-12T22:11:26.339846] [ADDR]314: dummy1    inet 192.0.2.1/24 scope global dummy1
       valid_lft forever preferred_lft forever

See also commit 7e0a889b5494 ("bridge: Do not print stray prefixes in
monitor mode") which fixed the same problem in the bridge tool.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

diff --git a/ip/ip_common.h b/ip/ip_common.h
index d3645a2cd126dd880c17b192b8c62689e6f89992..625311c25bce3db459187fdb0e2b92a50a5b325a 100644 (file)
--- a/ip/ip_common.h
+++ b/ip/ip_common.h
@@ -232,4 +232,5 @@ void print_stats64(FILE *fp, struct rtnl_link_stats64 *s,
                   const struct rtattr *carrier_changes, const char *what);
 void print_mpls_link_stats(FILE *fp, const struct mpls_link_stats *stats,
                           const char *indent);
+void print_headers(FILE *fp, const char *label);
 #endif /* _IP_COMMON_H_ */

diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index e3cb75418c1fdce6a8c7be20b3bcabe23f723a60..4e1f934fdbb48b0a6604752a122c695b335beb5a 100644 (file)
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -1052,6 +1052,8 @@ int print_linkinfo(struct nlmsghdr *n, void *arg)
        if (filter.slave_kind && match_link_kind(tb, filter.slave_kind, 1))
                return -1;
 
+       print_headers(fp, "[LINK]");
+
        if (n->nlmsg_type == RTM_DELLINK)
                print_bool(PRINT_ANY, "deleted", "Deleted ", true);
 
@@ -1598,6 +1600,8 @@ int print_addrinfo(struct nlmsghdr *n, void *arg)
                        return 0;
        }
 
+       print_headers(fp, "[ADDR]");
+
        if (n->nlmsg_type == RTM_DELADDR)
                print_bool(PRINT_ANY, "deleted", "Deleted ", true);
 

diff --git a/ip/ipaddrlabel.c b/ip/ipaddrlabel.c
index b045827a03ea7d4bce5612e77c5b6b04233a79bd..0f49bbee2648454250526c899c91b8057fdbb52a 100644 (file)
--- a/ip/ipaddrlabel.c
+++ b/ip/ipaddrlabel.c
@@ -46,6 +46,7 @@ int print_addrlabel(struct nlmsghdr *n, void *arg)
        struct ifaddrlblmsg *ifal = NLMSG_DATA(n);
        int len = n->nlmsg_len;
        struct rtattr *tb[IFAL_MAX+1];
+       FILE *fp = (FILE *)arg;
 
        if (n->nlmsg_type != RTM_NEWADDRLABEL && n->nlmsg_type != RTM_DELADDRLABEL)
                return 0;
@@ -56,6 +57,8 @@ int print_addrlabel(struct nlmsghdr *n, void *arg)
 
        parse_rtattr(tb, IFAL_MAX, IFAL_RTA(ifal), len);
 
+       print_headers(fp, "[ADDRLABEL]");
+
        open_json_object(NULL);
        if (n->nlmsg_type == RTM_DELADDRLABEL)
                print_bool(PRINT_ANY, "deleted", "Deleted ", true);

diff --git a/ip/ipmonitor.c b/ip/ipmonitor.c
index 9b055264ca7bf4e821074cc630f14c78597ef0e8..de67f2c90cbd55097433fa1d5aced4bd49b61826 100644 (file)
--- a/ip/ipmonitor.c
+++ b/ip/ipmonitor.c
@@ -22,6 +22,8 @@
 static void usage(void) __attribute__((noreturn));
 static int prefix_banner;
 int listen_all_nsid;
+struct rtnl_ctrl_data *ctrl_data;
+int do_monitor;
 
 static void usage(void)
 {
@@ -34,16 +36,19 @@ static void usage(void)
        exit(-1);
 }
 
-static void print_headers(FILE *fp, char *label, struct rtnl_ctrl_data *ctrl)
+void print_headers(FILE *fp, const char *label)
 {
+       if (!do_monitor)
+               return;
+
        if (timestamp)
                print_timestamp(fp);
 
        if (listen_all_nsid) {
-               if (ctrl == NULL || ctrl->nsid < 0)
+               if (ctrl_data == NULL || ctrl_data->nsid < 0)
                        fprintf(fp, "[nsid current]");
                else
-                       fprintf(fp, "[nsid %d]", ctrl->nsid);
+                       fprintf(fp, "[nsid %d]", ctrl_data->nsid);
        }
 
        if (prefix_banner)
@@ -55,6 +60,8 @@ static int accept_msg(struct rtnl_ctrl_data *ctrl,
 {
        FILE *fp = (FILE *)arg;
 
+       ctrl_data = ctrl;
+
        switch (n->nlmsg_type) {
        case RTM_NEWROUTE:
        case RTM_DELROUTE: {
@@ -71,11 +78,9 @@ static int accept_msg(struct rtnl_ctrl_data *ctrl,
 
                if (r->rtm_family == RTNL_FAMILY_IPMR ||
                    r->rtm_family == RTNL_FAMILY_IP6MR) {
-                       print_headers(fp, "[MROUTE]", ctrl);
                        print_mroute(n, arg);
                        return 0;
                } else {
-                       print_headers(fp, "[ROUTE]", ctrl);
                        print_route(n, arg);
                        return 0;
                }
@@ -83,32 +88,27 @@ static int accept_msg(struct rtnl_ctrl_data *ctrl,
 
        case RTM_NEWNEXTHOP:
        case RTM_DELNEXTHOP:
-               print_headers(fp, "[NEXTHOP]", ctrl);
                print_cache_nexthop(n, arg, true);
                return 0;
 
        case RTM_NEWNEXTHOPBUCKET:
        case RTM_DELNEXTHOPBUCKET:
-               print_headers(fp, "[NEXTHOPBUCKET]", ctrl);
                print_nexthop_bucket(n, arg);
                return 0;
 
        case RTM_NEWLINK:
        case RTM_DELLINK:
                ll_remember_index(n, NULL);
-               print_headers(fp, "[LINK]", ctrl);
                print_linkinfo(n, arg);
                return 0;
 
        case RTM_NEWADDR:
        case RTM_DELADDR:
-               print_headers(fp, "[ADDR]", ctrl);
                print_addrinfo(n, arg);
                return 0;
 
        case RTM_NEWADDRLABEL:
        case RTM_DELADDRLABEL:
-               print_headers(fp, "[ADDRLABEL]", ctrl);
                print_addrlabel(n, arg);
                return 0;
 
@@ -122,18 +122,15 @@ static int accept_msg(struct rtnl_ctrl_data *ctrl,
                                return 0;
                }
 
-               print_headers(fp, "[NEIGH]", ctrl);
                print_neigh(n, arg);
                return 0;
 
        case RTM_NEWPREFIX:
-               print_headers(fp, "[PREFIX]", ctrl);
                print_prefix(n, arg);
                return 0;
 
        case RTM_NEWRULE:
        case RTM_DELRULE:
-               print_headers(fp, "[RULE]", ctrl);
                print_rule(n, arg);
                return 0;
 
@@ -143,18 +140,15 @@ static int accept_msg(struct rtnl_ctrl_data *ctrl,
 
        case RTM_NEWNETCONF:
        case RTM_DELNETCONF:
-               print_headers(fp, "[NETCONF]", ctrl);
                print_netconf(ctrl, n, arg);
                return 0;
 
        case RTM_DELNSID:
        case RTM_NEWNSID:
-               print_headers(fp, "[NSID]", ctrl);
                print_nsid(n, arg);
                return 0;
 
        case RTM_NEWSTATS:
-               print_headers(fp, "[STATS]", ctrl);
                ipstats_print(n, arg);
                return 0;
 
@@ -196,6 +190,7 @@ int do_ipmonitor(int argc, char **argv)
        int ifindex = 0;
 
        rtnl_close(&rth);
+       do_monitor = 1;
 
        while (argc > 0) {
                if (matches(*argv, "file") == 0) {

diff --git a/ip/ipmroute.c b/ip/ipmroute.c
index b6d9e618f284cb8495506444150ea584a45c0a1d..da58d2953049d2a6200d02c10c67cc34be5e4161 100644 (file)
--- a/ip/ipmroute.c
+++ b/ip/ipmroute.c
@@ -97,6 +97,8 @@ int print_mroute(struct nlmsghdr *n, void *arg)
        if (inet_addr_match_rta(&filter.msrc, tb[RTA_SRC]))
                return 0;
 
+       print_headers(fp, "[MROUTE]");
+
        family = get_real_family(r->rtm_type, r->rtm_family);
 
        open_json_object(NULL);

diff --git a/ip/ipneigh.c b/ip/ipneigh.c
index ee14ffcccc468b2635d2d2e1bdd8066f3596aaa9..bd7f44e10426c7331deeb134ddf361071421f867 100644 (file)
--- a/ip/ipneigh.c
+++ b/ip/ipneigh.c
@@ -383,6 +383,8 @@ int print_neigh(struct nlmsghdr *n, void *arg)
                        return 0;
        }
 
+       print_headers(fp, "[NEIGH]");
+
        open_json_object(NULL);
        if (n->nlmsg_type == RTM_DELNEIGH)
                print_bool(PRINT_ANY, "deleted", "Deleted ", true);

diff --git a/ip/ipnetconf.c b/ip/ipnetconf.c
index a0c7e051bac5682718fccd1cadbc3e62bf895e8f..77147eb690978cd4d36ab0133b336a9d7bf50215 100644 (file)
--- a/ip/ipnetconf.c
+++ b/ip/ipnetconf.c
@@ -78,6 +78,8 @@ int print_netconf(struct rtnl_ctrl_data *ctrl, struct nlmsghdr *n, void *arg)
        if (filter.ifindex && filter.ifindex != ifindex)
                return 0;
 
+       print_headers(fp, "[NETCONF]");
+
        open_json_object(NULL);
        if (n->nlmsg_type == RTM_DELNETCONF)
                print_bool(PRINT_ANY, "deleted", "Deleted ", true);

diff --git a/ip/ipnetns.c b/ip/ipnetns.c
index 594b2ef15d0cce0fc777881e8b3450c4dec6c29a..972d7e9cf94936fa0a63e9668f5e5b7c6b16e11d 100644 (file)
--- a/ip/ipnetns.c
+++ b/ip/ipnetns.c
@@ -289,6 +289,8 @@ int print_nsid(struct nlmsghdr *n, void *arg)
                return -1;
        }
 
+       print_headers(fp, "[NSID]");
+
        open_json_object(NULL);
        if (n->nlmsg_type == RTM_DELNSID)
                print_bool(PRINT_ANY, "deleted", "Deleted ", true);

diff --git a/ip/ipnexthop.c b/ip/ipnexthop.c
index 8aa06de0557f0b3346507def00bf95720466c73d..91b731b05b367af71dee45b61ab5f4f00d9ac068 100644 (file)
--- a/ip/ipnexthop.c
+++ b/ip/ipnexthop.c
@@ -799,6 +799,9 @@ int print_cache_nexthop(struct nlmsghdr *n, void *arg, bool process_cache)
                fprintf(stderr, "Error parsing nexthop: %s\n", strerror(-err));
                return -1;
        }
+
+       print_headers(fp, "[NEXTHOP]");
+
        __print_nexthop_entry(fp, NULL, &nhe, n->nlmsg_type == RTM_DELNEXTHOP);
        print_string(PRINT_FP, NULL, "%s", "\n");
        fflush(fp);
@@ -839,6 +842,8 @@ int print_nexthop_bucket(struct nlmsghdr *n, void *arg)
 
        parse_rtattr_flags(tb, NHA_MAX, RTM_NHA(nhm), len, NLA_F_NESTED);
 
+       print_headers(fp, "[NEXTHOPBUCKET]");
+
        open_json_object(NULL);
 
        if (n->nlmsg_type == RTM_DELNEXTHOP)

diff --git a/ip/ipprefix.c b/ip/ipprefix.c
index c5704e5a50a5b3e1dc39f7fcffce553d8dbb6e93..4ec305241cebf656cc65c3a21c0e16914dba75c8 100644 (file)
--- a/ip/ipprefix.c
+++ b/ip/ipprefix.c
@@ -58,6 +58,8 @@ int print_prefix(struct nlmsghdr *n, void *arg)
 
        parse_rtattr(tb, RTA_MAX, RTM_RTA(prefix), len);
 
+       print_headers(fp, "[PREFIX]");
+
        if (tb[PREFIX_ADDRESS]) {
                fprintf(fp, "prefix %s/%u",
                        rt_addr_n2a_rta(family, tb[PREFIX_ADDRESS]),

diff --git a/ip/iproute.c b/ip/iproute.c
index 4466624049e922f526060e1a64115f20c815e333..9520729e58eb1b91eb7dd3044fd40abc4f1eb43d 100644 (file)
--- a/ip/iproute.c
+++ b/ip/iproute.c
@@ -818,6 +818,8 @@ int print_route(struct nlmsghdr *n, void *arg)
                        return 0;
        }
 
+       print_headers(fp, "[ROUTE]");
+
        open_json_object(NULL);
        if (n->nlmsg_type == RTM_DELROUTE)
                print_bool(PRINT_ANY, "deleted", "Deleted ", true);

diff --git a/ip/iprule.c b/ip/iprule.c
index e503e5c68cd3342794d22d565520347e60da9433..81938f2ed80c5ace851348eba8ff459f71543298 100644 (file)
--- a/ip/iprule.c
+++ b/ip/iprule.c
@@ -250,6 +250,8 @@ int print_rule(struct nlmsghdr *n, void *arg)
        if (!filter_nlmsg(n, tb, host_len))
                return 0;
 
+       print_headers(fp, "[RULE]");
+
        open_json_object(NULL);
        if (n->nlmsg_type == RTM_DELRULE)
                print_bool(PRINT_ANY, "deleted", "Deleted ", true);

diff --git a/ip/ipstats.c b/ip/ipstats.c
index 3f94ff1eb0a68322e925e354c03b1882f246d25b..cb9d9cbbe7f1a4dc25c2faea7c6f5d8b171f5805 100644 (file)
--- a/ip/ipstats.c
+++ b/ip/ipstats.c
@@ -741,7 +741,7 @@ static void ipstats_show_group(const struct ipstats_sel *sel)
 }
 
 static int
-ipstats_process_ifsm(struct nlmsghdr *answer,
+ipstats_process_ifsm(FILE *fp, struct nlmsghdr *answer,
                     struct ipstats_stat_enabled *enabled)
 {
        struct ipstats_stat_show_attrs show_attrs = {};
@@ -763,6 +763,8 @@ ipstats_process_ifsm(struct nlmsghdr *answer,
 
        dev = ll_index_to_name(show_attrs.ifsm->ifindex);
 
+       print_headers(fp, "[STATS]");
+
        for (i = 0; i < enabled->nenabled; i++) {
                const struct ipstats_stat_desc *desc = enabled->enabled[i].desc;
 
@@ -845,7 +847,7 @@ ipstats_show_one(int ifindex, struct ipstats_stat_enabled *enabled)
        ipstats_req_add_filters(&req, enabled);
        if (rtnl_talk(&rth, &req.nlh, &answer) < 0)
                return -2;
-       err = ipstats_process_ifsm(answer, enabled);
+       err = ipstats_process_ifsm(stdout, answer, enabled);
        free(answer);
 
        return err;
@@ -856,7 +858,7 @@ static int ipstats_dump_one(struct nlmsghdr *n, void *arg)
        struct ipstats_stat_enabled *enabled = arg;
        int rc;
 
-       rc = ipstats_process_ifsm(n, enabled);
+       rc = ipstats_process_ifsm(stdout, n, enabled);
        if (rc)
                return rc;
 
@@ -1352,7 +1354,7 @@ int ipstats_print(struct nlmsghdr *n, void *arg)
        FILE *fp = arg;
        int rc;
 
-       rc = ipstats_process_ifsm(n, &enabled);
+       rc = ipstats_process_ifsm(fp, n, &enabled);
        if (rc)
                return rc;